Belfast-born actor J.J. Murphy, who was slated to play Ser Denys Mallister, the oldest member of the Night’s Watch in the upcoming fifth season of Game of Thrones, died on Friday at the age of 86. He had begun filming his scenes in Northern Ireland — where much of the popular HBO drama is filmed — last week. HBO has not yet said whether the role would be recast or Murphy’s scenes would be re-written.

According to The Arts Council of Northern Ireland, Murphy served as a mentor to many young actors in the region, including Liam Neeson.

It’s not clear whether Murphy’s untimely death will cause a snag in production for the upcoming season, but — given the size of the role — it isn’t likely to have a significant impact on scheduling.